Lifting jack



J. A. MORRISON Feb. 21, 1933.

LIFTING JACK Filed Feb. 18] 1929 2 SheetsSheet uuuuuwuuunu nuuuuuu1 I: III" '29 gwuentoz JA Mar/"13012 351 i, I 61am,

JOHN MORRISON, F WARREN, OHIO, .ASSIGNOR,

Patented Feb. 21, 1933 UNITED STATES. PATENT OFFICE BY 'MESNE ASSIGNMENTS, TO

WALKER MANUFACTURING COMPANY, OF RAGINE, WISCONSIN, CORPORATION OF WISCONSIN Application filed February 18, 1929. SeriaI'No. 340,930.

The invention relates to jacks of the type used for raising automobiles, trucks, busses and the like and more particularly to a jack havinga plurality of lifting members in order to provide a considerable lifting range The object of the improvement is'to provide a jack having a hollow base within which is mounted a tubular lifting member, means being provided for raising this tubular member to the desired height, a lifting screw or other lifting member beingmovably mounted within the tubular member and provided at its upper end with a head for engagement with any desired portion of the vehicle to be lifted, means being provided for raising and lowering said lifting screw relative to the tubular lifting member.

A further object of the improvement is to provide a pawl or dog of peculiar construction for holding the tubular lifting member proved lifting ac k in the manner illustrated in. the accompanying drawings, in which Figure 1 is aside elevation of the lifting jack to which the invention pertains, showing the same adapted for use upon trucks, busses and other heavy vehicles, parts being broken away for the purpose of illustration;

Fig. 2, a section taken substantially on line 2-2, Fig. 1;

Fig. 3, a view similar to Fig. 2 of a modified form of the jack especially adapted for use upon lightervehicles; V

' Fig. 4, a-plan sectional view taken as upon the line 4-4, Fig. 3;

Fig. 5, a detached plan view of the top plate for the tubular lifting member; and

Fig. 6, an edge elevation of the same.

Similar numerals .refer to similar parts throu hout the drawings.

Be erring first to the form of jack illustrated in Figs. 1 and 2', which is especially adapted for lifting heavy vehicles such as trucks, busses and the like, the jack comprises generally the substantially tubularbase 10, the tubular lifting member 11 mounted for vertical movement in the base and the lifting screw 12 mounted for vertical movement in the tubular member.

The base 10 is preferably in the form of a malleable casting'having'the base plate 13 cast integrally with the tubular standard and preferably flanges 14.

For the purpose of raising thetubular member 11, with reference to the base, rack teeth 15 may be formed longitudinally upon one side thereof for engagement with the pin ion 16 preferably made integrally with the v ratchet teeth 20 may be formed upon the side ofthe tubularmember for engagement with a pawl 21 carried by the base, the lowermost tooth 20a being of considerably*greater depth than the remaining teeth in order to cooperate with the pawl 21 as a stop to limit the upward movement of the member 11 and prevent the same from being entirely disengaged from the base.

The pawl 21 is bifurcated as at 22 and'rests upon thesaddle 23 cast integrally with the cars 24 upon the base, the outer furcation 25' being extended downward for some considerable distance and preferably curved outward at its lower end as at 26, providing an operating handle forthe pawl which may be engaged by the foot or by the usual jackoperating handle to withdraw the upper end of the pawl from engagement with the ratchet teeth.

A coil spring 27 is seated in a socket 28, formed in ears 24, and engages the depending handle portion 25 of the pawl to normally urge the same to the position shown in Fig. 2, holding the side of the base, between the the upper end of the pawl in engagement with the rack teeth 20.

Thus, as the pinion 16 is rotated to raise the tubular member 11, the pawl 21 will ride over the rack teeth 20, dropping into position beneath each tooth after riding over the same, whereby the tubular member may be held in the desired raised position. I

The upper end of the tubular member is provided with an integral housing portion 29 having a preferably inclined tubular hearing portion 29a communicating therewith.

A combined nut and bevel gear 30 is housed within the housing 28, a ball race 31 being provided in the lower peripheral portion thereof for taking the thrust.

The bevel gear teeth 32 thereon mesh with a bevel pinion 33 upon the shaft 34 journaled within the bearing portion 29a, the socket 19 being fixed to the outer end of said shaft for receiving the usual operating handle.

The lifting screw 12 is threaded through the internal threads 36 of the combined nut and bevel gear and provided at its upper end with a lifting head 37 for engagement with any de-. sired portion of the vehicle to be lifted.

Inorder to provide a guide bearing for said screw and to permit easy access to the interior of the housing 28, a detachable top plate 39 is provided upon the housing, having the central guide bearing portion 40 to receive the screw.

This top plate is shown in detail in Figs.

5 and 6 and may be provided around its periphery with a pluralityof triangular lugs 41 for engagement in the notches 42 formed at the upper open end of the housing 28, each of these notches terminating in a triangular portion 43 to receive the triangular lugs 41 when the topplate is turned to the closed or locked position.

. For the purpose of easily turning the top plate to the locked or unlocked position, one or more bosses 44 may be provided upon the upper surface thereof for engagement with any suitable implement.

In. the operation of the jack, as above described, when it is desired to lift a vehicle, the jack, with the tubular member 11 and lifting screw 12 in lowered position, is placed beneath the spring, axle, or other portion of the vehicle adapted to be engaged by the lifting head. p

The usual jack operating handle is then engaged with the socket of the pinion 16 and the pinion is rotated thereby to raise the tubular member 11 until the lifting head 87 substantially engages the portion of the vehicle to be lifted. I

.Tlie tubular-member will be held in this raised position by means of'the pawl'Ql and the operating handle is then connected with the socket 19, and the pinion 33 is rotated in the vehicle has been raised to the desired height.

In lowering the jack, after the lifting screw has been lowered through opposite rotation of the pinion 33, the tubular member 11 may be lowered by depressing the handle portion 25 of the pawl sufficiently to disengagethe same from the ratchet teeth 20, the weight of the tubular member and screw being suflicient to lower the sameby gravity. p

In the form of the'jack shown in Figs. 3 and 4,which is especially designed for comparatively light vehicles such as pleasure cars and the like, all parts of the jack are substantially as above described excepting that the rack teeth 15 and pinion 16 are eliminated, spring means being provided in place of the same for automatically raising the tubular'member 11a when the pawl 21a is released. V r

A spring barrel 45is formed integrally with the standard 10a ofthe base, the axis thereof being parallel to the axis of the standard 10a. I v r V A coilspring 46 is housed within this barrel,,the lower end thereof resting upon the base plate 13aandthe upper end engaging an car 47 formed upon the side of the tubular member 11a. V

The spring are, which controls the pawl, is sufiiciently strong to hold the pawl in en gagement with the rack teeth2 0, against the a pressure of the spring 46.

k, The operation of this jack is the sameas that above described, excepting that whenthe pawl 21a is released from the ratchet teeth, the spring'46 will raise the tubular member 11a until the lifting head engages the vehicle to be lifted. The lifting screw may then be raised in the manner above described to lift the vehicle to the desired height.

It will be obvious from the above that the improved jack provides a considerable lifting range and may be easily operated by the usual jack operating'handle after the jack has been placed in position beneath'the vehicle to be lifted. I Y Y The jack shown in Figs. 1 and, 2 may be pushed into the desired position beneath the vehicle by means of the usual operating han dle, after which first the pinion 16 and later the bevel pinion 33 may be inturn operated by the same operating handle.

The form of jack shown in Fig. 3 may in the same manner he pushed to the desired position beneath the vehicle by means of the usual operating handle which may then be a proper direction to ralse the screw 12 until tubular member movable V longitudinally within the standard, a lifting screw carried by the tubular member, rack teeth upon the tubular member, a rack-engaging pinion mounted upon the standard, ratchet teeth upon the tubular member peripherally spaced from said rack teeth, a bifurcated pawl pivotally mounted on the standard and engaging the ratchet teeth to hold the tubular member in adjusted position, and an en-- larged tooth upon the bottom of the tubular member below said ratchet teeth for coacting with said pawl to limit the upward movement of said tubular member.

2. A lifting jack including a standard, a

tubular member movable longitudinally within the standard, a lifting screw carried by the tubular member, rack teeth upon the tubular member, a rack-engaging pinion mounted upon the standard, ratchet teeth upon the tubular member peripherally spaced from said rack teeth, a bifurcated pawl pivotally mounted on the standard and engaging the ratchet teeth tohold the tubular member in adjusted position, and means upon the bottom of the tubular member below said ratchet teeth for coacting with said pawl to limit the upward movement of said tubular member. 7

In testimony that I claim the above I have hereunto subscribed my name.

JOHN A. MORRISON. 

